The trust funder charged in the Soho House bathtub strangling of his swimsuit designer girlfriend will see his ramblings to cops come back to haunt him at trial, thanks to a Manhattan judge’s ruling today.

In the hours after beautiful Sylvie Cachay was found half nude and submerged in an overflowing tub at the upscale hotel — but prior to his arrest — Nicholas Brooks made numerous voluntary statements to police, and they are all admissible, Manhattan Supreme Court Justice Bonnie Wittner ruled.

Among the most self-incriminating are Brooks’ admission to cop that he and Cachay had argued about his history of using escorts, but that “it was not a big deal.”

Brooks, 27, also claimed that Cachay was asleep in bed — not in the tub — when he left for a night of drinking and cocaine use. That statement may prove the most legally risky of all. Prosecutors say that by the time Brooks left, the overflowing tub had already affected downstairs guests, who called hotel staff to complain minutes before Brooks was recorded leaving on hotel surveillance.

The judge has yet to rule on the admissibility of Brooks’ post-arrest statements, which include this damaging question to cops in an unmarked car en route from the Sixth Precinct to Central Booking: “How much could I get for something like this?”

Brooks had been living off a trust fund set up by his composer dad, Joseph Brooks, who won an Oscar for the 70s love dirge “You Light Up My Life.” The elder Brooks committed suicide in May of 2011, while under indictment for an alleged string of rapes and molestations of a dozen wannabe actresses who’d come to his Upper East Side apartment for “auditions” to non-existent movie projects.

A murder trial date in the Cachay case has tentatively been set for June 4.

“This is very good news for the prosecution,” Cachay family lawyer Susan Karten said today’s hearing.

Cachay’s mother Sylvia, who also attended the hearing along with the father, Antonio, added, “We realize we are going to see justice, and I am sure New York justice is going to be in our favor.”